Accessing Computers Using On Screen Keyboards

By Dianna Fong-Lee
This article and reviews originally appeared in the May/June 1999 issue of Occupational Therapy Now magazine published by the Canadian Association of Occupational Therapists.

The ability to manipulate the computer cursor using a mouse or other pointing peripheral can allow computer access for individuals who do not have sufficient control to use a standard keyboard. By moving the mouse pointer over a visual representation of a keyboard that appears on the computer screen, a character may be selected by producing a simple button click or alternative selection method. The character is then placed onto a running programme as if it had come from the computers own keyboard. Using an on-screen keyboard to bypass the standard keyboard is not a new solution. However, recent products offer options that can accommodate for a wide range of motor, perceptual and cognitive limitations.

Options to change the size of the display window, individual keys or characters as well as the size and appearance of the pointer are features which may enhance targetting skills for individuals with visual as well as motor limitations. Passive selection of a key by "dwell time" or "autoclick" may be an essential feature for individuals who are unable to produce a button click independently. Some on-screen keyboards even offer scanning input with switch(es) for individuals who are unable to navigate the mouse but are able to depress a switch to select a key that is highlighted. These features may be critical for individuals with a degenerative condition as they lose function or conversely, a child progressing through physical or developmental milestones would benefit from the ability to change these options.

Since most users of on-screen keyboards use a single digit on a mouse or limited movements with an alternative pointing device, rate enhancement techniques and options to customize the keyboard layout should be available to enhance speed of output and avoid fatigue. It should be possible to select a keyboard layout that is arranged according to frequency of use or to design a more efficient pattern other than the standard keyboard. Word prediction or abbreviation expansion are rate enhancement techniques that attempt to decrease the number of keystrokes required when generating text by predicting or encoding words. These techniques may be built into the programme to avoid having to purchase separate packages and to ensure compatibility.

The biggest improvements made by developers of on-screen keyboards are features that decrease visual, perceptual and cognitive demands. In addition to the options for changing the size of keyboards, it is now possible to change the colour of a key or background, and to customize visual feedback or auditory feedback. Useful options that may enhance visual access of the on-screen keyboard include click feedback or speaking keys, to indicate the selected key. To accommodate for cognitive or languages needs, the ability to incorporate picture communication symbols, whole words or phrases on a keyboard layout, supports students at various literacy levels to achieve greater independence in text generation.

Within the last five years, there has been an increase in the number of on-screen keyboards available for Windows and Macintosh based systems. The costs for these programmes range from $300 to $500. While these are average costs, there are low end, on-screen keyboards offered as shareware or freeware, as well as high end keyboards with extra options that are priced well over $1000. Potential users should first establish the desired pointing device; for example, mouse, trackball, headpointer, etc. and selection method; for example button click, alternative switch or dwell/autoclick, before comparing the features of more than one on-screen keyboard.

References

Fong-Lee, D. (1993). Visual keyboards. Canadian Journal of Occupational Therapy, 60, 102.

Hecht, J. & Heinisch, B. (1998, October). A comparative overview of on-screen keyboards. Presentation at the Closing Gap Conference, Minneapolis, MN. USA.

Discover:Screen*
Don Johnston Inc. (www.donjohnston.com)
Cost: $448 Cdn.

Originally developed for Macintosh systems, the new Windows 95/PC version of Discover:Screen, is a product of Don Johnston Inc. and IBM Special Needs Systems designed to provide access to all standard keyboard functions using any compatible mouse-type device. Discover:Screen provides text-to-speech voice to speak keys as they are selected. In addition, speech or a ‘beep’ feedback is available to assist with visual access or letter recognition by providing an auditory cue as the keys are highlighted. An autoclick feature is available and the length of time that a key must be highlighted before it is automatically selected can be changed easily. Literacy development may be enhanced through Discover:Screen as it supports single letter writers as well as whole word writers; for example, complete words and phrases may appear on some setups to assist in efficient sentence construction.

A range of pre-programmed Discover:Screen setup files are available and can be attached to desired application programmes for automatic activation. For example, an alphabetical setup might be attached to a word processing programme or a numbers setup might be launched with the Windows 95 calculator. While there are 13 setups built into the programme, they are not intended to address every unique problem or challenge. Fortunately, there are blank setups available for creating custom setups however, this is not always an easy task for the novice user.

What is quite surprising is the lack of flexibility for quick fine-tuning or resizing of the keyboard to accommodate for variations in motor control. One would expect the Windows 95/PC version to feature the same ability to shrink or enlarge the keyboard by dragging the lower right corner of the keyboard window. Perhaps the Windows 95/PC version was released too soon as larger keyboards are only possible by selecting a pre-programmed setup or using the design mode to create a custom setup. Unfortunately, the key sizes and keyboards offered in the blank setups are quite limited and inappropriate for individuals who may require a keyboard that covers almost half of the screen for successful pointing.

In comparison with other on-screen keyboards available for Windows based systems, there are a few shortcomings worth noting. Rate enhancement techniques such as word prediction or abbreviation expansion have not been built into Discover:Screen. Co:writer, a compatible word prediction package developed by the same manufacturer is available but at an additional cost. The pointer shape is a square that nicely highlights individual keys with a border. However, it is not possible to change the size or shape of the pointer to accommodate for individuals with visual perceptual limitations who may work better with a brightly coloured or larger pointer such as an icon of a finger or a large arrow. Lastly, for individuals who need scanning access, this keyboard does not provide that option. Overall, Discover:Screen is a welcome addition for Windows users, however future releases would do well to address some of the identified options that are available on other on-screen keyboards.

— Dianna Fong Lee

Software for this review was provided by Bridges, Inglewood, Ontario. 1 (800) 353-1107.

On-screen keyboards to consider: